Here's another issue, the question of morality.
It is said that he wrote a heroic epic with clear good-bad duality, so this is why the book lacks in shade of grey, the genre itself prevents that.
The problem is, there is no good and bad in LotR at all, if we consider what everyone is doing. Tolkien tells us who is the shining paragon of virtue and who is the despicable villain, but this isn't really come through the happenings, we have to take his word on it.
Here's this guy, his stuff was stolen, and wants it back. He is very evil, we should hate him.
Here's this guy, who doesn't care about nothing just broods all day, and humiliates a hard working women for their lack of knowledge. He is the good guy, we should like him.
Here's this guy facing immeasurable danger, with the potential destruction of everything him and his ancestors worked hard for, then some upstart rogue with a known meddler in his company comes and tries to tell him he fucked up and he should bow to him, and despite this he tries his best, but the weight is to much to his psyche and breaks. This is also a bad guy, we should hate him.
Etc.
Thank you Tolkien.